Devices, systems and methods for medicament delivery

ABSTRACT

Apparatuses for automatic medicament injection and methods for manufacturing automatic medicament injectors are described herein. In some embodiments, an apparatus includes a housing, a needle, an energy storage member, an actuator, a locking member, and a needle guard. The needle is configured to move between a first position and a second position. In its first position, the needle is contained within the housing. In its second position, at least a portion of the needle extends from the housing. The energy storage member has a first configuration and a second configuration and is configured to produce a force when moving between its first configuration and its second configuration to move the needle from its first position to its second position. The actuator is configured to move the energy storage member from its first configuration to its second configuration. The locking member is movably coupled to the distal end portion of the housing such that the locking member can be moved between a first position and a second position. In its first position, the locking member is configured to engage the actuator to prevent the actuator from moving the energy storage member to the second configuration. The needle guard is removably coupled to at least one of the distal end portion of the housing or a base movably coupled to the distal end portion of the housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/562,061 entitled “Devices, Systems and Methods forMedicament Delivery,” filed Nov. 21, 2006, which is acontinuation-in-part of U.S. patent application Ser. No. 10/515,571entitled “Devices, Systems and Methods for Medicament Delivery,” filedNov. 23, 2004, which is a national stage filing under 35 U.S.C. §371 ofInternational Patent Application No. PCT/US2004/039386, entitled“Devices, Systems and Methods for Medicament Delivery,” filed Nov. 23,2004, each of which is incorporated herein by reference in its entirety.This application is a continuation-in-part of U.S. patent applicationSer. No. 10/572,148, entitled “Devices, Systems and Methods forMedicament Delivery,” filed Mar. 16, 2006, which is a national stagefiling under 35 U.S.C. §371 of International Patent Application No.PCT/US2006/003415, entitled “Devices, Systems and Methods for MedicamentDelivery,” filed Feb. 1, 2006, which claims priority to U.S. ProvisionalApplication Ser. No. 60/648,822, entitled “Devices, Systems and Methodsfor Medicament Delivery,” filed Feb. 1, 2005 and U.S. ProvisionalApplication Ser. No. 60/731,886, entitled “Auto-Injector with Feedback,”filed Oct. 31, 2005, each of which is incorporated herein by referencein its entirety.

BACKGROUND

The invention relates generally to a medical device, and moreparticularly to a medicament delivery device for automatically injectinga medicament into a body of a patient.

Exposure to certain substances, such as, for example, peanuts,shellfish, bee venom, certain drugs, toxins, and the like, can causeallergic reactions in some individuals. Such allergic reactions can, attimes, lead to anaphylactic shock, which can cause a sharp drop in bloodpressure, hives, and/or severe airway constriction. Accordingly,responding rapidly to mitigate the effects from such exposures canprevent injury and/or death. For example, in certain situations, aninjection of epinephrine (i.e., adrenaline) can provide substantialand/or complete relief from the allergic reaction. In other situations,for example, an injection of an antidote to a toxin can greatly reduceand/or eliminate the harm potentially caused by the exposure.

Because emergency medical facilities may not be available when anindividual is suffering from an allergic reaction, some individualscarry an auto-injector to rapidly self-administer a medicament inresponse to an allergic reaction.

Some known auto-injectors include a locking cap at the proximal end ofthe auto-injector to prevent inadvertent actuation and a needle cover atthe distal end of the auto-injector. Such a configuration can, at times,cause a user to become confused as to which end of the auto-injector isthe “needle end” (i.e., the distal end) and which end of theauto-injector is the “actuation end” (i.e., the proximal end). As such,in some situations, a user may mistakenly actuate the knownauto-injector away from the intended injection site. Such an error canresult, for example, in the auto-injector being actuated into the user'sthumb and/or finger. Furthermore, the locking cap can be removed priorto removal of the needle cover, thus allowing the auto-injector to beactuated before the needle cover has been removed.

Some known auto-injectors include a needle cover that collapses orbuckles when the auto-injector is actuated and the needle breaks throughthe cover. In application, this leaves the needle cover bunched around aportion of the needle, which can cause the needle cover to interferewith penetration of the needle into the user.

Manufacturing techniques of known auto-injectors require much of themanufacturing process of an auto-injector to occur in a sterileenvironment. In particular, a sterile environment is needed for fillingthe auto-injector with a medicament and for assembly of theauto-injector. Providing and maintaining a sterile environment duringthe entire manufacturing process, however, can be quite expensive.

Thus, a need exists for an auto-injector that can be more convenientlycarried by a user and that can be actuated from its distal end. A needexists for an auto-injector that cannot be actuated until the needlecover has been removed. A need also exists for an auto-injector with aneedle cover that will not interfere with, but will ensure, consistentpenetration of the needle. Furthermore, a need exists for a moreeconomical method of manufacturing auto-injectors.

SUMMARY

Apparatuses for automatic medicament injection and methods formanufacturing automatic medicament injectors are described herein. Insome embodiments, an apparatus includes a housing, a needle, an energystorage member, an actuator, a locking member, and a needle guard. Theneedle is configured to move between a first position and a secondposition. In its first position, the needle is contained within thehousing. In its second position, at least a portion of the needleextends from the housing. The energy storage member has a firstconfiguration and a second configuration and is configured to produce aforce when moving between its first configuration and its secondconfiguration to move the needle from its first position to its secondposition. The actuator is configured to move the energy storage memberfrom its first configuration to its second configuration. The lockingmember is movably coupled to the distal end portion of the housing suchthat the locking member can be moved between a first position and asecond position. In its first position, the locking member is configuredto engage the actuator to prevent the actuator from moving the energystorage member to the second configuration. The needle guard isremovably coupled to at least one of the distal end portion of thehousing or a base movably coupled to the distal end portion of thehousing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are schematic illustrations of an auto-injector accordingto an embodiment of the invention in a first configuration and a secondconfiguration, respectively.

FIG. 3 is a perspective view of an auto-injector according to anembodiment of the invention.

FIG. 4 is a perspective view of the auto-injector illustrated in FIG. 3in a first configuration, with at least a portion of the auto-injectorillustrated in phantom lines for ease of reference.

FIG. 5 is a front view of the auto-injector illustrated in FIGS. 3 and 4in a first configuration.

FIG. 6 is a perspective view of the auto-injector illustrated in FIG. 3showing an assembly according to an embodiment of the invention beingremoved.

FIG. 7 is a front view of the auto-injector illustrated in FIG. 3showing a member according to an embodiment of the invention beingremoved.

FIG. 8 is an exploded perspective view of a portion of the auto-injectorillustrated in FIG. 6.

FIG. 9 is a cross-sectional view of a component illustrated in FIG. 8.

FIG. 10 is a perspective view of a component illustrated in FIG. 8.

FIG. 11 is a perspective view of a member of the auto-injectorillustrated in FIG. 7.

FIG. 12 is a perspective view of a portion of the auto-injectorillustrated in FIGS. 3 and 7.

FIG. 13 is a perspective view of a portion of the auto-injectorillustrated in FIGS. 3 and 12.

FIG. 14 is a partially exploded perspective view of a base of theauto-injector illustrated in FIG. 12.

FIG. 15 is an exploded perspective view of a portion of theauto-injector shown in FIG. 4.

FIG. 16 is a front view of a component of the auto-injector shown inFIG. 15.

FIG. 17 is a front view of the auto-injector illustrated in FIG. 5 in asecond configuration.

FIG. 18 is a perspective view of a portion of the auto-injector shown inFIG. 17.

FIGS. 19 and 20 are perspective views of a portion of the auto-injectorshown in FIG. 18.

FIG. 21 is a top view of the housing of the auto-injector shown in FIG.17.

FIG. 22 is a cross-sectional view of the housing taken along line 22-22in FIG. 21.

FIG. 23 is front view of the auto-injector illustrated in FIGS. 5 and 17in a third configuration.

FIG. 24 is a front view of the portion of the auto-injector labeled as24 in FIG. 23.

FIG. 25 is a perspective view of a portion of the auto-injector shown inFIG. 23.

FIG. 26 is a cross-sectional view of a portion of the auto-injector asshown in FIG. 23.

FIG. 27 is a perspective view of a portion of the auto-injector as shownin FIG. 23.

FIG. 28 is an exploded perspective view of a portion the auto-injectoras shown in FIG. 23.

FIG. 29 is front view of the auto-injector illustrated in FIGS. 5, 17and 24 in a fourth configuration.

FIG. 30 is a front view of a portion of the auto-injector illustrated inFIGS. 5, 17, 24 and 29 in a fifth configuration.

FIG. 31 is a front view of the auto-injector illustrated in FIGS. 5, 17,24, 29 and 30 in a sixth configuration.

FIG. 32 is a front view of an auto-injector according to an embodimentof the invention.

FIGS. 33 and 34 are perspective views of an auto-injector according toan embodiment of the invention in a first configuration and a secondconfiguration respectively.

FIGS. 35-37 are front views of an auto-injector according to anembodiment of the invention in a first, second, and third configurationrespectively.

FIG. 38 is a front view of a portion of the auto-injector illustrated inFIGS. 36 and 37.

FIG. 39 is an exploded perspective view of the portion of theauto-injector illustrated in FIG. 38.

FIGS. 40 and 41 are perspective views of an auto-injector according toan embodiment of the invention in a first configuration and a secondconfiguration respectively.

FIG. 42 is a front view of a portion of the auto-injector illustrated inFIGS. 40 and 41.

FIG. 43 is a perspective view of the portion of the auto-injectorillustrated in FIGS. 42.

FIG. 44 is a flowchart illustrating a method according to an embodimentof the invention.

DETAILED DESCRIPTION

Apparatuses and methods for automatic medicament injection and methodsfor manufacturing automatic medicament injectors (also referred toherein as “auto-injectors”) are described herein. In some embodiments,an apparatus includes a housing, a needle, an energy storage member, anactuator, a locking member, and a needle guard. The needle is configuredto move between a first position and a second position. In its firstposition, the needle is contained within the housing. In its secondposition, at least a portion of the needle extends from the housing. Theenergy storage member has a first configuration and a secondconfiguration and is configured to produce a force when moving betweenits first configuration and its second configuration to move the needlefrom its first position to its second position. The actuator isconfigured to move the energy storage member from its firstconfiguration to its second configuration. The locking member is movablycoupled to the distal end portion of the housing such that the lockingmember can be moved between a first position and a second position. Inits first position, the locking member is configured to engage theactuator to prevent the actuator from moving the energy storage memberto the second configuration. The needle guard is removably coupled to atleast one of the distal end portion of the housing or a base movablycoupled to the distal end portion of the housing.

In some embodiments, an apparatus includes a housing and a safety guard.The safety guard includes a locking portion and a needle guard portion.The locking portion is configured to inhibit actuation of a medicamentdelivery device. The needle guard portion is configured to substantiallycover a needle of the medicament delivery device. The safety guard has afirst position and a second position. In its first position, the safetyguard is configured to be selectively coupled to at least one of thehousing or a base movably coupled to the housing. In its secondposition, the safety guard is removed from the housing.

In some embodiments, an apparatus includes a needle guard configured tocover at least a portion of a needle of a medical injector. The needleguard is configured to substantially prevent microbes from passingthrough the needle guard. The needle guard is configured to allow asterilant gas to pass through the needle guard.

In some embodiments, an apparatus includes a housing, a medicamentinjector, and a porous needle guard. The medicament injector isdisposable within the housing and includes a needle. The needle has afirst position and a second position. In its first position, the needleis contained within the housing. In its second position, at least aportion of the needle extends from the housing. The porous needle guardis removably coupled to the distal end portion of the housing. Theporous needle guard is constructed from a microbial resistant material.

A method of manufacturing an automatic medicament injector includesinserting at least a portion of a needle into a needle hub disposed in ahousing. A needle cover is installed over at least a portion of theneedle to substantially cover a portion of the needle extending from theneedle hub. The needle is sterilized after the needle cover is installedover at least a portion of the needle.

FIGS. 1 and 2 are schematic illustrations of an auto-injector 2002according to an embodiment of the invention in a first configuration anda second configuration, respectively. The auto-injector 2002 includes ahousing 2110 that contains a medicament container 2262, an energystorage member 2410, a release member 2540 and an injection member 2212.The medicament container 2262, which can be, for example, a pre-filledcartridge, a vial, an ampule or the like, is movably disposed within thehousing 2110. The medicament container 2262 contains a medicament 2268,such as, for example, epinephrine. As illustrated, the medicamentcontainer 2262 can be moved, as indicated by arrow B in FIG. 2, alongits longitudinal axis Lm between a first position (FIG. 1) and a secondposition (FIG. 2). When the medicament container 2262 is in its first(or retracted) position, the medicament container 2262 is spaced apartfrom the injection member 2212. When the medicament container 2262 is inthe second (or advanced) position, the medicament container 2262 isplaced in fluid communication with the injection member 2212. In thismanner, when the medicament container 2262 is in the second (oradvanced) position, the medicament 2268 can be conveyed via theinjection member 2212 from the medicament container 2262 into a body ofa patient. The injection member 2212 can be, for example, a needle, anozzle or the like.

The energy storage member 2410, which can be any suitable device forstoring energy, such as, for example, a spring, a battery, a compressedgas cylinder or the like, is also movably disposed within the housing2110. As shown, the energy storage member 2410 defines a longitudinalaxis Le that is offset from the longitudinal axis Lm of the medicamentcontainer 2262. The energy storage member 2410 can be moved, asindicated by arrow A in FIG. 2, within the housing 2110 along itslongitudinal axis Le between a first position (FIG. 1) and a secondposition (FIG. 2). When the energy storage member 2410 is in its firstposition, the energy storage member 2410 has a first potential energy.When the energy storage member 2410 is in its second position, theenergy storage member 2410 has a second potential energy that is lessthan the first potential energy. When the energy storage member 2410moves from its first position to its second position, it converts atleast a portion of its first potential energy into kinetic energy tomove the medicament container 2262 between its first position and itssecond position.

Said another way, the movement of the energy storage member 2410 fromits first position to its second position results in the production of aforce that acts upon the medicament container 2262 to move themedicament container 2262 between its first position and its secondposition. The non-coaxial relationship between the longitudinal axis Lmof the medicament container 2262 and the longitudinal axis Le of theenergy storage member 2410 allows the medicament container 2262 and theenergy storage member 2410 to be arranged within the housing 2110 in anynumber of different configurations. In this manner, the auto-injector2002 can have any number of different sizes and shapes, such as, forexample, a substantially rectangular shape.

The release member 2540 is disposed within the housing 2110 and isconfigured to selectively deploy the energy storage member 2410 from itsfirst position to its second position. The release member 2540 can beany suitable mechanism for moving the energy storage member 2410, suchas, for example, a mechanical linkage, a spring-loaded rod or the like.In this manner, a user can actuate the auto-injector by manipulating aportion of the release member 2540.

FIG. 3 is a perspective view of an auto-injector 3002 according to anembodiment of the invention in a first configuration. The auto-injector3002 includes a housing 3110 having a proximal end portion 3112 and adistal end portion 3114. The distal end portion 3114 of the housing 3110includes a protrusion 3142 to help a user grasp and retain the housing3110 when using the auto-injector 3002. Said another way, the protrusion3142 is configured to prevent the auto-injector 3002 from slipping fromthe user's grasp during use. A base 3520 is movably coupled to thedistal end portion 3114 of the housing 3110. A needle guard assembly3810 is removably coupled to the base 3520. Similarly, a safety lock3710 is removably coupled to the base 3520. To inject a medicament intothe body, the distal end portion 3114 of the housing 3110 is orientedtowards the user such that the base 3520 is in contact with the portionof the body where the injection is to be made. The base 3520 is thenmoved towards the proximal end 3112 of the housing 3110 to actuate theauto-injector 3002. The housing 3110 also includes a transparent statuswindow 3118 (see FIG. 22) to allow a user to determine the status of theauto-injector 3002 or the medicament contained therein.

FIG. 4 is a perspective view of the auto-injector 3002 showing thehousing 3110 in phantom lines so that the components contained withinthe housing 3110 can be more clearly seen. For clarity, FIG. 4 shows theauto-injector 3002 without the needle guard assembly 3810 and the safetylock 3710. Similarly, FIG. 5 is a front view of the auto-injector 3002showing the housing 3110 in phantom lines. The auto-injector 3002includes a medicament injector 3210 and a movable member 3312 engagedwith the medicament injector 3210, each of which are disposed within thehousing 3110. The auto-injector 3002 also includes a system actuator3510, a compressed gas container 3412 and a gas release mechanism 3612.

The medicament injector 3210 includes a carrier 3250 that is movablewithin the housing 3110, a medicament container 3262 and a needle 3212.The medicament container 3262 is coupled to the carrier 3250. The needle3212 is disposed within a needle hub portion 3223 (see FIG. 8) of thecarrier 3250 to allow the needle to be placed in fluid communicationwith the medicament container 3262 during an injection event.

The movable member 3312 includes a proximal end portion 3316 and adistal end portion 3318. The proximal end portion 3316 includes asurface 3322 that, together with the housing 3110, defines a gas chamber3120. Said another way, the surface 3322 defines a portion of a boundaryof the gas chamber 3120. The distal end portion 3318 is disposed withinthe medicament container 3262. In use, the movable member 3312 movestowards the distal end portion 3114 of the housing 3110, as indicated byarrow C, in response to a force produced by a pressurized gas on thesurface 3322 of the movable member 3312. As a result, the movable member3312 and the medicament injector 3250 are moved towards the distal endportion 3114 of the housing 3110, thereby exposing the needle 3212 fromthe housing 3110. The movable member 3312 then continues to move withinthe medicament container 3262 to expel a medicament from the medicamentcontainer 3262 through the needle 3212.

The auto-injector 3002 is actuated by the system actuator 3510, which isconfigured to move the compressed gas container 3412 into contact withthe gas release mechanism 3612. The gas release mechanism 3612 puncturesa portion of the compressed gas container 3412 to release thepressurized gas contained therein into the gas chamber 3120 defined bythe housing 3110.

The system actuator 3510 includes a rod 3540, a spring 3560 and a springretainer 3570. The rod 3540 has a proximal end portion 3542 and a distalend portion 3544. The proximal end portion 3542 of the rod 3540 iscoupled to the compressed gas container 3412. The distal end portion3544 of the rod 3540 is coupled to the spring retainer 3570 by twoprojections 3548, which can be moved inwardly towards each other todecouple the rod 3540 from the spring retainer 3570, as discussed below.

The spring 3560 is disposed about the rod 3540 in a compressed statesuch that the spring 3560 is retained by the proximal end portion 3542of the rod 3540 and the spring retainer 3570. In this manner, the rod3540 is spring-loaded such that when the distal end portion 3544 of therod 3540 is decoupled from the spring retainer 3570, the force of thespring 3560 causes the rod 3540, and therefore the compressed gascontainer 3412, to move proximally as indicated by arrow D and intocontact with the gas release mechanism 3612.

The base 3520 defines an opening 3522 (shown in FIG. 13) configured toreceive a portion of the projections 3548 when the base is moved towardsthe proximal end 3112 of the housing 3110, as indicated by arrow E. Whenthe projections 3548 are received within the opening 3522, they aremoved together causing the distal end portion 3544 of the rod 3540 to bereleased from the spring retainer 3570. In some embodiments, the opening3522 extends though at least a portion of the base 3520. In someembodiments, the opening 3522 extends completely through the base 3520,for example, such that a locking portion of a safety guard (discussed indetail below) can be inserted through the opening.

As shown in FIGS. 4 and 5, the medicament injector 3210 defines alongitudinal axis Lm that is non-coaxial with the longitudinal axis Ledefined by the compressed gas container 3412. Accordingly, themedicament injector 3210, the compressed gas container 3412 and thesystem actuator 3510 are arranged within the housing 3110 such that thehousing has a substantially rectangular shape. Moreover, the non-coaxialrelationship between the medicament injector 3210 and the compressed gascontainer 3412 allows the auto-injector 3002 to be actuated bymanipulating the base 3520, which is located at the distal end portion3114 of the housing 3110.

The use and actuation of the auto-injector 3002 includes severaldiscrete operations. First, the auto-injector 3002 is enabled byremoving the needle guard 3810 and the safety lock 3710 (see FIGS. 6 and7). Second, the auto-injector 3002 is actuated by moving the base 3520proximally towards the housing 3110. Third, when actuated, thecompressed gas container 3412 engages the gas release mechanism 3612,which causes the pressurized gas to be released into the gas chamber3120 (see FIG. 17). Fourth, the pressurized gas produces a force thatcauses the movable member 3312 and the medicament injector 3210 to movedistally within the housing 3110 (see FIG. 23). The movement of themedicament injector 3210 causes the needle 3212 to extend from distalend portion 3114 of the housing 3110 and the base 3520. This operationcan be referred to as the “needle insertion” operation. Fifth, when themedicament injector 3210 has completed its movement (i.e., the needleinsertion operation is complete), the movable member 3312 continues tomove the medicament container 3262 distally within the carrier 3250. Thecontinued movement of the medicament container 3262 places the needle3212 in fluid communication with the medicament container 3262, therebyallowing the medicament to be injected (see FIG. 29). Sixth, the forcefrom the pressurized gas causes the movable member 3312 to move withinthe medicament container 3262, thereby expelling the medicament throughthe needle 3212 (see FIG. 30). This operation can be referred to as the“injection operation.” Seventh, upon completion of the injection, thepressurized gas is released from the gas chamber 3120, thereby allowingthe medicament injector 3210 and the movable member 3312 to be movedproximally within the housing. This operation can be referred to as the“retraction operation” (see FIG. 31). A detailed description of thecomponents contained in the auto-injector 3002 and how they cooperate toperform each of these operations is discussed below.

Prior to use, the auto-injector 3002 must first be enabled by firstremoving the needle guard 3810 and then removing the safety lock, orlocking member, 3710. As illustrated by arrow G in FIG. 6, the needleguard 3810 is removed by pulling it distally. Similarly, as illustratedby arrow H in FIG. 7, the safety lock 3710 is removed by pulling itsubstantially normal to the longitudinal axis Le of the compressed gascontainer 3412. Said another way, the safety lock 3710 is removed bymoving it in a direction substantially normal to the direction that theneedle guard 3810 is moved or to the longitudinal axis Lm of the needle(as shown in FIG. 5). As described in more detail herein, in someembodiments, the needle guard 3810 and the safety lock 3710 arecooperatively arranged to prevent the safety lock 3710 from beingremoved before the needle guard 3810 has been removed. Such anarrangement prevents the auto-injector 3002 from being actuated whilethe needle guard 3810 is in place.

As illustrated in FIGS. 8 and 9, the needle guard 3810 includes a sheath3820 and a sheath retainer 3840. The sheath 3820 has a proximal endportion 3822 and a distal end portion 3824 and defines an opening 3826configured to receive a portion of the needle 3212 when the needle guard3810 is in a first (or installed) position. Said another way, the sheath3820 is an inner member of the needle guard 3810 configured tosubstantially cover at least a portion of the needle 3212 when theneedle guard is in a first position, and the sheath retainer 3840 is anouter member of the needle guard. The sheath 3820 further defines arecessed portion 3828 within the opening 3826 that engages acorresponding protrusion 3238 defined by an outer surface 3236 of theneedle hub 3223. In this manner, when the needle guard 3810 is in itsfirst position, the sheath 3820 is removably coupled to the needle hub3223. In some embodiments, the recessed portion 3828 and the protrusion3238 form a seal that is resistant to microbial penetration.

The sheath 3820 can be constructed from any suitable material. Forexample the sheath can be constructed from polyethylene, including highdensity polyethylene, polypropylene, polytetrafluoroethylene,thermoplastic polyurethane, rubber or any other elastomer or polymer. Insome embodiments, the sheath 3820 is constructed from a rigid material.A rigid needle sheath can reduce the likelihood of needle sticks duringthe manufacturing process and can inhibit crumpling of the sheath aroundthe needle during insertion of the needle into bodily tissue. In otherembodiments, the sheath can be constructed from a flexible material. Insome embodiments, the sheath 3820 is constructed from a materialconfigured to resist or substantially prevent microbial penetrationtherethrough, and thus can maintain sterility of a needle receivedtherein.

The sheath 3820 can be configured for use with one or more sterilizationmethods. In other words, the sheath can be configured to allowsterilization of the needle when the sheath is disposed over the needleand coupled to the needle hub. In some embodiments, the sheath 3820 isconfigured to allow a sterilant gas or other sterilizing agent to passtherethrough. For example, the sheath can include a valve configured toallow passage of the sterilant gas. In another example, the sheath isconstructed of a porous material, such as a porous material configuredto allow passage of the sterilant gas through the material whilepreventing microbes from passing therethrough.

The sheath retainer 3840 has a proximal portion 3842 and a distalportion 3844. The proximal portion 3842 of the sheath retainer 3840includes a protrusion 3856 that engages a corresponding recess 3526 inthe base 3520 (see FIG. 14) to removably couple the sheath retainer 3840to the base 3520. The distal portion 3844 of the sheath retainer 3840defines an opening 3846 through which the distal end portion 3824 of thesheath 3820 is disposed. The distal portion 3844 of the sheath retainer3840 includes a series of retaining tabs 3852 that engage the distal endportion 3824 of the sheath 3820 to couple the sheath 3820 to the sheathretainer 3840. In this manner, when the sheath retainer 3840 is moveddistally away from the base 3520 into a second (or removed) position, asshown in FIG. 6, the sheath 3820 is removed from the needle 3212.Moreover, this arrangement allows the sheath 3820 to be disposed aboutthe needle 3212 independently from when the sheath retainer 3840 iscoupled to the sheath 3820. As such, the two-piece construction of theneedle guard provides flexibility during manufacturing, for example,because the sheath retainer can be installed after the sheath has beendisposed about the needle and the needle sterilized. The distal portion3844 of the sheath retainer 3840 also includes a protrusion 3848 to aidthe user when grasping the needle guard 3810.

When the needle guard 3810 is in its first (or installed) position, thesheath retainer 3840 is disposed within a recess 3720 defined by one ofthe extended portions 3716 of the safety lock 3710 (see FIG. 11). Thisarrangement prevents the safety lock 3710 from being removed when theneedle guard 3810 is in its first position, which in turn, prevents theauto-injector 3002 from being actuated when the needle guard 3810 is inits first position.

As illustrated in FIG. 8, the outer surface of the needle guard 3810 (orsheath retainer 3840 specifically) can include an indicia 3850 toinstruct the user in operating an auto-injector. The indicia 3850includes a numeral to indicate the order of operation and an arrow toindicate the direction in which the needle guard 3810 should be moved.

After the needle guard 3810 is removed, the user must then remove thesafety lock 3710, as indicated in FIG. 7. As shown in FIG. 11, thesafety lock 3710 is a U-shaped member having a first end 3712 and asecond end 3714. The second end 3714 of the safety lock 3710 includestwo extended portions 3716, each of which includes an inwardly facingprotrusion 3718. When the safety lock 3710 is in its first (or locked)position, the extended portions 3716 extend around a portion of the base3520 to space the base 3520 apart from the distal end portion 3114 ofthe housing 3110. As shown in FIG. 12, the protrusions 3718 areconfigured engage a portion of the base 3520 to removably couple thesafety lock 3710 in its first position. One of the extended portions3716 defines a recess 3720 that receives the sheath retainer 3840 whenthe needle guard 3810 is in its first position, as discussed above.Although only one extended portion 3716 is shown as including a recess3720, in some embodiments both extended portions 3716 can include arecess 3720 to receive the sheath retainer 3840. The safety lock 3710can be engaged with the needle guard 3810 to prevent movement of thesafety lock 3710 when the needle guard 3810 is in place in any suitablemanner. For example, in some embodiments, the sheath retainer includesprotrusions that are received within corresponding openings defined bythe safety lock. In some embodiments, the safety lock includesprotrusions that are received within corresponding openings defined bythe sheath retainer.

The first end 3712 of the safety lock 3710 includes a locking protrusion3722 that extends inwardly. As shown in FIG. 12, when the safety lock3710 is in its first position, the locking protrusion 3722 extendsbetween the projections 3548 of the rod 3540 and obstructs an opening3522 of the base 3520. In this manner, when the safety lock 3710 is inits first position, the base 3520 cannot be moved proximally to allowthe projections 3548 to be received within the opening 3522. Thearrangement of the locking protrusion 3722 also prevents the projections3548 from being moved inwardly towards each other. Accordingly, when thesafety lock 3710 is in its first position, the auto-injector 3002 cannotbe actuated.

The outer surface 3724 of the first end 3712 of the safety lock 3710includes a series of ridges 3726 to allow the user to more easily gripthe safety lock 3710. The outer surface 3724 of the first end 3712 ofthe safety lock 3710 also includes an indicia 3728 to instruct the userin operating the auto-injector 3002. As shown in FIG. 11, the indicia3728 includes a numeral to indicate the order of operation and an arrowto indicate the direction in which the safety lock 3710 should be moved.In some embodiments, the indicia 3728 can include different colors,detailed instructions or any other suitable indicia to instruct theuser. In other embodiments, the indicia 3728 can protrude from thesafety lock 3710 to aid the user when grasping the safety lock 3710.

After being enabled, the auto-injector 3002 can then be actuated bymoving the base 3520 proximally towards the housing 3110, as indicatedby arrow I in FIG. 13. As shown in FIGS. 14 and 22, the base 3520defines two openings 3536 that receive corresponding attachmentprotrusions 3150 disposed on the distal end portion 3114 of the housing3110. In this manner, the movement and/or alignment of the base 3520relative to the housing 3110 is guided by the attachment protrusions3150 and the openings 3536 (see FIG. 22).

Each attachment protrusion 3150 is secured within its correspondingopening 3536 by a lock washer 3534. The lock washers 3534 each define anopening 3535 that receives a portion of the attachment protrusion 3150.The lock washers 3534 are disposed within slots 3533 defined by the base3520 so that the openings 3535 are aligned with the attachmentprotrusions 3150. The openings 3535 are configured to allow the lockwashers 3534 to move proximally relative to the attachment protrusions3150, but to prevent movement of the lock washers 3534 distally relativeto the attachment protrusions 3150. In this manner, when the attachmentprotrusions 3150 are disposed within the openings 3535 of the lockwashers 3534, the base 3520 becomes fixedly coupled to the housing 3110.Moreover, after the base 3520 is moved proximally relative to thehousing 3110, the lock washers 3534 prevent the base 3520 from returningto its initial position. Said another way, the arrangement of the lockwashers 3534 prevents the base 3520 from being “kicked back” after theauto-injector 3002 has been actuated.

The base 3520 also defines a needle opening 3532, a recess 3526 and tworetraction spring pockets 3531. The needle opening 3532 receives aportion of the needle guard 3810 when the needle guard is in its firstposition. Additionally, when the auto-injector is in its thirdconfiguration (see FIG. 23), the needle 3212 extends through the needleopening 3532. As described above, the recess 3526 receives thecorresponding protrusion 3856 on the sheath retainer 3840 to removablycouple the needle guard 3810 to the base 3520. As will be described inmore detail herein, the retraction spring pockets 3531 receive a portionof the retraction springs 3350.

As shown in FIG. 14, the base 3520 includes two opposing taperedsurfaces 3524 that define an opening 3522 configured to receive acorresponding tapered surface 3550 of the projections 3548 when the baseis moved proximally towards the housing 3110. The opening 3522 canextend through the base 3520 or through at least a portion of the base.When the projections 3548 are received within the tapered opening 3522,they are moved together as indicated by arrows J in FIG. 13. The inwardmovement of the projections 3548 causes the rod 3540 to becomedisengaged from the spring retainer 3570, thereby allowing the rod 3540to be moved proximally along its longitudinal axis as the spring 3560expands. A more detailed description of the components included in thesystem actuator 3510 is provided below with reference to FIGS. 15 and16.

The system actuator 3510 includes a rod 3540, a spring 3560 disposedabout the rod 3540 and a spring retainer 3570. As described in moredetail herein, the spring retainer 3570 retains both the spring 3560 andthe rod 3540. The spring retainer 3570 includes a first surface 3572, asecond surface 3574 and a series of outwardly extending engagement tabs3576. The spring retainer 3570 is disposed within the gas containeropening 3124 defined by the housing 3110 (see FIG. 22) such that theengagement tabs 3576 engage the interior surface 3123 of the housing3110 to produce an interference fit. In this manner, the spring retainer3570 is fixedly disposed within the housing 3110.

The rod 3540 has a proximal end portion 3542 and a distal end portion3544. The distal end portion 3544 of the rod 3540 includes twoextensions 3552 disposed apart from each other to define an opening 3554therebetween. Each extension 3552 includes a projection 3548 having atapered surface 3550 and an engagement surface 3549. When the rod 3540is in its first (or engaged) position, the engagement surfaces 3549engage the second surface 3574 of the spring retainer 3570 to preventthe rod 3540 from moving proximally along its longitudinal axis. Asdescribed above, when the base 3520 is moved proximally towards thehousing 3110, the tapered surfaces 3550 of the projections 3548cooperate with the corresponding tapered surfaces 3524 of the base 3520to move the extensions 3552 inwardly towards each other. The inwardmotion of the extensions 3552 causes the engagement surfaces 3549 tobecome disengaged from the second surface 3574 of the spring retainer3570, thereby allowing the rod 3540 to move between its first positionto a second (or actuated) position.

The proximal end portion 3542 of the rod 3540 includes a retentionportion 3545 having a first surface 3547 and a second surface 3546. Thefirst surface 3547 of the retention portion 3545 engages the distalportion 3416 of the compressed gas container 3412. The second surface3546 of the retention portion 3545 engages a proximal end 3562 of thespring 3560. Similarly, the first surface 3572 of the spring retainer3570 engages a distal end 3564 of the spring 3560. In this manner, whenthe rod 3540 is in its first position, the spring 3560 can be compressedbetween the spring retainer 3570 and the retention portion 3545 of therod 3540. Accordingly, when the rod 3540 is disengaged from the springretainer 3570, the force imparted by the spring 3560 on the retentionportion 3545 of the rod 3540 causes the rod 3540 to move proximally intoits second position.

The proximal end portion 3542 of the rod 3540 is coupled to thecompressed gas container 3412 by a connector 3580, which is secured tothe distal end portion 3416 of the compressed gas container 3412 by asecuring member 3588. The connector 3580 includes a proximal end portion3582 and a distal end portion 3584. The distal end portion 3584 of theconnector 3580 is disposed within the opening 3554 defined between theextensions 3552. In this manner, the connector 3580 is retained by theproximal end portion 3542 of the rod 3540. As will be described in moredetail, the distal end portion 3584 of the connector 3580 includeslocking tabs 3587.

The proximal end portion 3582 of the connector 3580 includes engagementportions 3586 that engage the distal end portion 3416 of the compressedgas container 3412. The engagement portions 3586 are coupled to thecompressed gas container 3412 by the securing member 3588, which can be,for example, a shrink wrap, an elastic band or the like. In otherembodiments, the engagement portions 3586 can produce an interferencefit with the compressed gas container 3412, thereby eliminating the needfor a securing member 3588.

Because the rod 3540 is coupled to the compressed gas container 3412,when the rod 3540 is moved from its first (engaged) position to itssecond (actuated) position, the compressed gas container 3412 is movedproximally within the housing 3110 into engagement with the gas releasemechanism 3612. FIG. 17 shows the auto-injector in a secondconfiguration, in which the compressed gas container 3412 is engagedwith the gas release mechanism 3612. When in the second configuration,the compressed gas contained within the compressed gas container 3412 isreleased to actuate the medicament injector 3210. A more detaileddescription of the gas release process is provided below with referenceto FIGS. 18 through 22.

FIG. 18 shows an exploded view of the system actuator 3510, thecompressed gas container 3412 and the gas release mechanism 3612, eachof which are disposed within the gas container opening 3124 defined bythe housing 3110 (see FIG. 22). As shown, the compressed gas container3412, the system actuator 3510 and the gas release mechanism 3612 arearranged substantially coaxial with each other. As previously discussed,when the auto-injector 3002 is actuated, the compressed gas container3412 is moved proximally within the gas container opening 3124 definedby the housing 3110, as indicated by the arrow K in FIG. 18, until theproximal end 3414 of the compressed gas container 3412 engages the gasrelease mechanism 3612.

As shown in FIGS. 19 and 20, the gas release mechanism 3612 includes acap 3630 and a puncturing element 3620 coupled to and disposed withinthe cap 3630. The puncturing element has a proximal end 3622 and adistal end 3624. The distal end 3624 of the puncturing element 3620defines a sharp point 3626 configured to puncture the proximal end 3414of the compressed gas container 3412. The puncturing element 3620defines an opening 3627 extending from its distal end 3624 to itsproximal end 3622.

The cap 3630 has a proximal end 3632, an outer surface 3635 and an innersurface 3636. The inner surface 3636 of the cap 3630 defines an opening3634 that receives the proximal end 3414 of the compressed gas container3412 when the auto-injector 3002 is in its second configuration. Theproximal end 3632 of the cap 3630 defines an opening 3638 therethroughand a channel 3640 in fluid communication with the opening 3638. Theopening 3638 receives the proximal end 3622 of the puncturing element3620 to couple the puncturing element 3620 to the cap 3630. Thepuncturing element 3620 is disposed within the cap 3630 such that whenthe compressed gas container 3412 is moved into the opening 3634, thedistal end 3624 of the puncturing element 3620 punctures the proximalend 3414 of the compressed gas container 3412.

The cap 3630 is disposed within the gas container opening 3124 such thatthe outer surface 3635 of the cap 3630 engages the inner surface 3123 ofthe housing 3110. In some embodiments, the outer surface 3635 of the cap3630 can be sized to produce an interference fit with the inner surface3123 of the housing 3110. In other embodiments, the cap 3630 can befixedly coupled within the gas container opening 3124 using an adhesiveor any other suitable attachment mechanism.

The cap 3630 is oriented within the gas container opening 3124 so thatthe channel 3640 is aligned with and in fluid communication with the gaspassageway 3126 defined by the housing 3110. Moreover, when oriented inthis manner, the protrusion 3642 on the proximal end 3632 of the cap3630 obstructs a portion of the gas passageway 3126, which can bemanufactured as a through-hole, to fluidically isolate the gaspassageway 3126 from an area outside of the housing 3110. After theproximal end 3414 of the compressed gas container 3412 has beenpunctured, pressurized gas flows from the compressed gas container 3412into the gas passageway 3126 through the opening 3627 defined by thepuncturing element 3620 and the channel 3640 defined by the proximal end3632 of the cap 3630.

The inner surface 3636 of the cap 3630 is configured to hermeticallyseal the proximal end 3414 of the compressed gas container 3412 withinthe opening 3638. This arrangement prevents pressurized gas from leakingaround the compressed gas container 3412 to an area outside of thehousing 3110 after the proximal end 3414 of the compressed gas container3412 has been punctured. In some embodiments, the inner surface 3636 issized to produce an interference fit with the compressed gas container3412. In other embodiments, the cap 3630 includes a separate sealingmember, such as, for example, an o-ring, to seal the proximal end 3414of the compressed gas container 3412 within the opening 3638.

After the compressed gas container 3412 is moved into engagement withthe gas release mechanism 3612, the position of the compressed gascontainer 3412 within the gas container opening 3124 is maintained bythe locking tabs 3587 on the connector 3580. As shown in FIG. 15, eachlocking tab 3587 includes a pointed portion that is angled outwardlyfrom the connector 3580. This arrangement allows the connector 3580 tomove proximally within the gas container opening 3124 of the housing3110, but prevents the connector 3580 from moving distally within thegas container opening 3124 of the housing 3110. Said another way, thearrangement of the locking tabs 3587 prevents the compressed gascontainer 3412 from being “kicked back” when exposed to the forceproduced by the pressurized gas as the pressurized gas is released.

As previously discussed, the pressurized gas released from thecompressed gas container 3412 produces a force on the boundary of thegas chamber 3120, including the surface 3322 of the movable member 3312.This force causes the movable member 3312 and the medicament injector3210 move together distally within the housing 3110, as shown by arrowL, placing the auto-injector 3002 in a third configuration, as shown inFIG. 23. When in the third configuration, the distal end 3214 of theneedle 3212 is disposed through the opening 3532 defined by the base3520 to an area outside of the auto-injector 3002. Moreover, as shown inFIG. 24, when the auto-injector 3002 is in the third configuration, theproximal end 3216 of the needle 3212 remains spaced apart from thedistal end 3266 of the medicament container 3210, ensuring that theneedle 3212 remains fluidically isolated from the medicament container3210. In this manner, the needle 3212 can be inserted into a patient asthe auto-injector 3002 moves between its second configuration (FIG. 17)and its third configuration (FIG. 23) without injecting the medicamentuntil after insertion is completed. A more detailed description of themedicament injector 3210 and the movable member 3312 is provided belowwith reference to FIGS. 23 through 28.

As previously described, the medicament injector 3210 includes a carrier3250, a medicament container 3262 and a needle 3212. The carrier 3250has a lower portion 3222 and an upper portion 3252. The lower portion3222 of the carrier 3250 includes a needle hub 3223, which contains theneedle 3212. The lower portion 3222 of the carrier 3250 also defines anopening 3224 configured to receive a distal portion 3266 the medicamentcontainer 3262. As shown in FIG. 25, the needle 3212 is coupled to theneedle hub 3223 such that the proximal end 3216 of the needle 3212 isdisposed within the opening 3224 and the distal end 3214 of the needle3212 extends distally outside of the needle hub 3223.

The inner surface 3228 of the lower portion 3222 defining the opening3224 includes a protrusion 3226. The protrusion 3226 is configured toengage a corresponding recess 3272 defined by a sealing cap 3270disposed at the distal portion 3266 of the medicament container 3262(see FIG. 28) to secure the medicament container 3262 within the opening3224 such that the proximal end 3216 of the needle 3212 is spaced apartfrom the distal end 3266 of the medicament container 3210. Theprotrusion 3226 and the recess 3272 are configured such that theprotrusion 3226 will become disengaged from the recess 3272 when theforce applied exceeds a predetermined value. Said another way, theprotrusion 3226 and the recess 3272 collectively form a removablesnap-fit that allows the medicament container 3262 to be moved withinthe opening 3224 when the force applied to the medicament container 3262exceeds a predetermined value. This arrangement ensures that the needle3212 remains fluidically isolated from the medicament container 3262during the insertion operation.

The outer surface 3236 of the lower portion 3222 includes a protrusion3238. As previously described, the protrusion 3238 is configured toengage a corresponding recess portion 3828 within the opening 3826 ofthe sheath 3820 (see FIG. 9) to removably couple the sheath 3820 to theneedle hub 3223.

The lower portion 3222 of the carrier 3250 also defines two retractionspring pockets 3242 each receiving the proximal end 3352 of a retractionspring 3350. As previously discussed, the distal end 3354 of eachretraction spring 3350 is retained within the retraction spring pockets3531 defined by the base 3520. As shown in FIG. 24, when the carrier3250 moves distally within the housing 3110, the retraction springs 3350are compressed and therefore bias the carrier 3250 towards the proximalportion 3112 of the housing 3110.

The upper portion 3252 of the carrier 3250 defines an opening 3256configured to receive a proximal portion 3264 of the medicamentcontainer 3262 and includes two valve actuators 3254. As described inmore detail herein, the valve actuators 3254 are configured to engage agas relief valve 3328 to allow the pressurized gas contained within thegas chamber 3120 to escape when the injection event is complete.

The upper portion 3252 of the carrier 3250 defines four gas reliefpassageways 3258. Similarly, the lower portion 3222 of the carrier 3250defines four gas relief passageways 3244. When the pressurized gas isreleased from the gas chamber 3120, the gas relief passageways 3258,3244 provide a fluid path to allow the pressurized gas to flow from thegas chamber 3120 to an area outside of the housing 3110.

As described above, the movable member 3312 includes a proximal endportion 3316 and a distal end portion 3318. The distal end portion 3318includes a piston 3324 disposed within the proximal portion 3264 of themedicament container 3262, such that the piston engages a plunger 3284contained within the medicament container 3262, as shown in FIG. 28.

The proximal end portion 3316 includes a surface 3322 that defines aportion of a boundary of the gas chamber 3120. As shown in FIG. 27, theproximal end portion 3316 defines two openings 3326 therethrough, eachof which are in fluid communication between the gas chamber 3120 and theinterior of the housing 3110 outside the gas chamber 3120. The proximalend portion 3316 further defines a slot 3330 that receives a gas reliefvalve 3328, which can be, for example, a flexible rubber member. The gasrelief valve 3328 is positioned within the slot 3330 and adjacent theopenings 3326 to selectively allow fluid communication between the gaschamber 3120 and the area outside the gas chamber 3120 through theopenings 3326. The operation of the gas relief valve 3328 is discussedin more detail herein.

The proximal end portion 3316 of the movable member 3312 also includes aseal 3314 that engages a portion the inner surface 3122 of the housing3110 (see FIG. 22) to fluidically isolate the gas chamber 3120. Althoughthe seal 3314 is shown as being an o-ring seal, in some embodiments, theseal need not be a separate component, but can rather be a portion ofthe proximal end portion 3316 of the movable member 3312.

When the needle insertion operation is completed, the lower portion 3222of the carrier 3250 engages the base 3520, preventing further distalmovement of the carrier 3250 within the housing. Because the distalmotion of the carrier 3250 is opposed, the force exerted by thepressurized gas on the surface 3322 of the movable member 3312 increasesuntil the protrusion 3226 of the lower portion 3222 of the carrier 3250and the recess 3272 defined by sealing cap 3270 of the medicamentcontainer 3262 become disengaged. Accordingly, the medicament container3262 to moves distally relative to the carrier 3250, placing theauto-injector 3002 in a fourth configuration, as shown in FIG. 29. Whenmoving between the third configuration (FIG. 24) and the fourthconfiguration (FIG. 29), the proximal end 3216 of the needle 3212pierces the liner 3271 within the sealing cap 3270 disposed at thedistal portion 3266 of the medicament container 3262. As such, when inthe fourth configuration, the proximal end 3216 of the needle 3212 is influid communication with the medicament container 3262, thereby allowingthe medicament to be injected.

Once the needle 3212 is in fluid communication with the medicamentcontainer 3262, the force from the pressurized gas causes the piston3324 of the movable member 3312 to move the plunger 3284 within themedicament container 3262, as shown by arrow M in FIG. 30, therebyexpelling the medicament through the needle 3212. The piston 3324 andthe plunger 3284 move a predetermined distance within the medicamentcontainer 3262, placing the auto-injector 3002 in a fifth configuration,as shown in FIG. 30. When the auto-injector 3002 is in the fifthconfiguration, the injection of medicament is complete.

When the auto-injector 3002 is in its fifth configuration, proximalportion 3316 of the movable member 3312 is in contact with the upperportion 3252 of the carrier 3250, thereby preventing further movement ofthe piston 3324 within the medicament container 3262. In this manner,the distance through which the piston 3324 travels, and therefore theamount of medicament injected, can be controlled.

Additionally, when the auto-injector 3002 is in its fifth configuration,the valve actuators 3254 are disposed within the openings 3326 such thatthe valve actuators 3254 displace the gas relief valve 3328.Accordingly, the pressurized gas contained within the gas chamber 3120can flow from the gas chamber 3120 to the area within the housing 3310outside of the gas chamber 3310. As previously discussed, the gas reliefpassageways 3258, 3244 provide a fluid path to allow the pressurized gasto flow from the gas chamber 3120, through the opening 3532 defined bythe base 3520 and to an area outside of the housing 3110.

When the pressurized gas flows out of the gas chamber 3120, the pressureexerted on the surface 3322 of the movable member 3312 decreases.Accordingly, the force exerted by the retraction springs 3350 issufficient to move the medicament injector 3210 and the movable member3312 proximally within the housing 3110, as shown by arrow N, into asixth (or retracted) configuration as shown in FIG. 31. Because themedicament injector 3210 and the movable member 3312 move together, thevalve actuators 3254 remain disposed within the openings 3326 as theauto-injector 3002 moves into the sixth configuration. In this manner,the gas relief valve 3328 remains displaced and the openings 3326 remainin fluid communication with the gas chamber 3120 and the area within thehousing 3310 outside of the gas chamber 3310 independent of the positionof the movable member 3312. Such an arrangement ensures that all of thepressurized gas flows out of the gas chamber 3120, thereby ensuring thatthe medicament injector 3210 and the movable member 3312 return to thesixth configuration and do not oscillate between the sixth configurationand the fifth configuration, which could lead to the needle 3212 notbeing fully retracted into the housing 3110.

Although the auto-injector 3002 has been shown and described having ahousing 3110 having a substantially rectangular shape, in someembodiments, an auto-injector can have a housing having any shape. Insome embodiments, for example, an auto-injector can have a substantiallycylindrical shape. In other embodiments, for example, the auto-injectorcan have an irregular and/or asymmetrical shape.

Although the auto-injector 3002 has been shown and described asincluding a protrusion 3142 disposed at the distal end portion 3114 ofthe housing 3110 to help a user grasp and retain the housing 3110, insome embodiments, a protrusion can be disposed anywhere along thehousing. In other embodiments, a protrusion can symmetrically surroundthe distal portion of the housing. In yet other embodiments, the housingof an auto-injector can include a gripping portion configured to help auser grasp and retain the housing. The gripping portion can include, forexample, a textured surface, a contoured surface, a surface having anadhesive that forms a tacky surface to adhere to the user's hand or thelike. For example, FIG. 32 shows an auto-injector 4002 according to anembodiment of the invention having a housing 4110. The housing 4110includes a proximal end portion 4112, a distal end portion 4114 and agripping portion 4140. The distal end portion 4114 of the housing 4110includes a protrusion 4142 to prevent the user's hand from slipping offof the distal end portion 4114 of the housing 4110 when using theauto-injector 4002. Similarly, the gripping portion 4140 includes aseries of contours 4144 that engage the user's fingers to help the usergrasp and retain the housing 4110 when the auto-injector 4002 is in use.

The distal end portion 4114 of the housing 4110 also includes twoalignment marks 4146 to guide the user when placing the auto-injector4002 against the body. Although the alignment marks 4146 are shown asmarkings on the housing 4110, in other embodiments, the alignment markscan include protrusions, openings or the like.

Certain components of the auto-injector 3002 are shown and described asbeing coupled together via protrusions and mating recesses. Theprotrusions and/or recesses can be disposed on any of the components tobe coupled together and need not be limited to only a certain component.For example, the base 3520 is shown as defining two openings 3536 thatreceive corresponding attachment protrusions 3150 on the distal endportion 3114 of the housing 3110. In some embodiments, however, theprotrusions can be disposed on the base and the mating recesses can bedefined by the distal end portion of the housing. In other embodiments,two or more components can be coupled together in any suitable way,which need not include protrusions and mating recesses. For example, insome embodiments, two or more components can be coupled together viamating shoulders, clips, adhesive and the like.

Similarly, although certain components of the auto-injector 3002 areshown and described as being constructed from multiple separatecomponents, in some embodiments, such components can be monolithicallyconstructed. For example, the carrier 3250 is shown and described asincluding an upper portion 3252 and a lower portion 3222 that areconstructed separately and then coupled together. In other embodiments,a carrier can be constructed monolithically.

Although the sheath retainer 3840 of the auto-injector 3002 has beenshown and described as including a protrusion 3856 that engages acorresponding recess 3526 in the base 3520 to removably couple thesheath retainer 3840 to the base 3520, in some embodiments, the sheathretainer can include a protrusion configured to engage a differentcorresponding recess on the auto-injector 3002. For example, the sheathretainer can include a protrusion configured to engage a correspondingrecess in the distal end portion 3114 of the housing 3110.

Although the safety lock (or locking member) 3710 of the auto-injector3002 has been shown and described as including a protrusion 3718configured to engage a base 3520 movably coupled to the housing 3110, insome embodiments, the safety lock can include a protrusion configured toengage a different portion of the auto-injector 3002. For example, thesafety lock can include a protrusion configured to engage a portion ofthe housing 3110, such as the distal end portion 3114 of the housing3110, to removably couple the safety lock in its first position.

Although the base 3520 of the auto-injector 3002 has been shown anddescribed covering almost the entire distal end portion 3114 of thehousing 3110, in some embodiments, a base configured to actuate theauto-injector can be disposed about only a portion of the distal end ofthe housing. For example, in some embodiments, an auto-injector caninclude a button extending from the distal end portion of the housingconfigured to engage and release the system actuator.

Although the rod 3540 is shown and described as being an elongatedmember that is released by being elastically deformed, in someembodiments, a rod can be of any suitable shape and in any suitableorientation within the housing. Moreover, in some embodiments, a rod canbe released by being plastically deformed. For example, in someembodiments, a rod can be disposed along an axis that is offset from thelongitudinal axis of the energy storage member. In some embodiments, therod can be configured to break upon actuation.

Although the gas release mechanism 3612 is shown and described asincluding a puncturing element 3620 to puncture a portion of thecompressed gas container 3262, the gas release mechanism 3612 need notinclude a puncturing element 3620. For example, in some embodiments, thegas release mechanism can include an actuator configured to actuate avalve that controls the flow of gas out of the compressed gas container.For example, in some embodiments, a compressed gas container can includea spring loaded check ball and the gas release mechanism can include anactuator configured to engage and depress the check ball to releasepressurized gas from the compressed gas container.

Although the distance through which the piston 3324 travels, andtherefore the amount of medicament injected, is shown and described asbeing controlled by configuring the movable member 3312 such that it isin contact with the upper portion 3252 of the carrier 3250 when theauto-injector 3002 is in its fifth configuration, in other embodiments,any suitable method of controlling the piston travel can be employed.For example, in some embodiments, piston travel can be limited byincluding a protrusion within the medicament container, such as a neckedportion, that limits the motion of the piston within the medicamentcontainer. In other embodiments, the housing can include a protrusion tolimit the motion of the movable member. In yet other embodiments, thevalve actuator can be configured to actuate the gas relief valve whenthe piston has moved a predetermined distance within the medicamentcontainer. In yet other embodiments, a combination of each of the abovemethods for controlling the piston travel can be employed.

Although the auto-injector 3002 is shown and described as having sixdifferent configurations that are different from each other, in someembodiments, certain configuration of an auto-injector can be the sameas another configuration. For example, in some embodiments, a“pre-actuation configuration can be the same as a “retracted”configuration. In other embodiments, any of the functions describedabove can be accomplished when an auto-injector is moved between anynumber of different configurations.

In some embodiments, as illustrated in FIGS. 33-34, an auto-injector3004 includes a housing 3140 and a needle guard 3812 removably coupledto the distal end portion 3144 of the housing 3140. The needle guard3812 includes a sheath 3111 and a sheath retaining portion 3113. Theneedle guard 3812 has a first position and a second position. In itsfirst position, the needle guard 3812 is coupled to the housing 3140.For example, the sheath retaining portion 3113 of the needle guard 3812is configured to substantially cover or encase the distal end portion3144 of the housing 3140 when the needle guard is in its first position.In its second position, the needle guard 3812 is removed from thehousing 3140. The sheath 3111 is coupled to the sheath retaining portion3113 similar to the coupling of the sheath 3820 and sheath retainer 3840as described in detail above with reference to FIG. 8. As such, as thesheath retaining portion 3113 is moved distally in the direction ofarrow P, the sheath 3111 is also moved distally and removed from thehousing 3140. Once the needle guard 3812 is moved to its second (orremoved) position, the safety lock 3730 is accessible. The safety lock3730 is removed from the housing 3140 by pulling the safety lock in adirection that is substantially normal to the direction in which theneedle guard 3812 is removed, such as in the direction of arrow Q asillustrated in FIG. 34.

In some embodiments, as illustrated in FIGS. 35-37, an auto-injector3006 includes a housing 3116, a safety guard 3130, and a distal end cap3160. The distal end cap 3160 is configured to selectively engage or becoupled to the housing 3116. The distal end cap 3160 preventsinadvertent actuation of the auto-injector 3006 by substantiallycovering at least a portion of the safety guard 3130 when the distal endcap 3160 is engaged with or coupled to the housing 3116.

The distal end cap 3160 has a first position and a second position. Inits first position, illustrated in FIG. 35, the distal end cap 3160 isremovably coupled to or engaged with the distal end portion 3156 of thehousing 3116. In its second position, illustrated in FIG. 36, the distalend cap 3160 is removed from the housing 3116. The distal end cap 3160must be removed from the auto-injector 3006 before the auto-injector canbe enabled for use, thus preventing inadvertent actuation of the device.Furthermore, the distal end cap 3160 provides an additional barrier tocontamination of the needle and the medicament disposed therein. Thedistal end cap 3160 can have a series of ridges or other tactilemechanism for assisting a user in gripping and/or removing the distalend cap. The distal end cap 3160 is replaceable. As such, if the distalend cap 3160 is removed before a user intends to use the auto-injector3006, the user can put the distal end cap back in its first positionwithout actuating or jeopardizing the sterility of the device.

Once the distal end cap 3160 is removed, the safety guard 3130 isexposed and can be removed. With the safety guard 3130 in place, theauto-injector 3006 can not be actuated. The safety guard 3130,illustrated in FIGS. 38-39, includes a base portion 3132, a lockingportion 3134, and a needle guard portion 3136. The locking portion 3134and needle guard portion 3136 extend proximally from the base portion3132. The base includes a first end 3146 and a second end 3148. Thelocking portion 3134 is disposed adjacent the first end 3146 andincludes a first engagement portion 3128. A second engagement portion3138 is disposed adjacent the second end 3148 of the base portion 3132.

The needle guard portion 3136 of the safety guard 3130 includes a sheath3152 and a sheath retaining portion 3154. The sheath 3152, which issimilar to sheath 3820 discussed in detail above, defines an openingconfigured to receive at least a portion of a needle of theauto-injector and is removably coupled to the sheath retaining portion3154. The sheath retaining portion 3154 is couplable to the housing 3116or to the base 3158 which is coupled to the housing.

The safety guard 3130 has a first position and a second position. In itsfirst position, illustrated in FIG. 36, the safety guard 3130 is coupledto the distal end 3156 of the housing 3116. For example, the safetyguard 3130 can be coupled to a base 3128 movably coupled to the distalend 3156 of the housing 3116. In its second position, shown in FIG. 37,the safety guard 3130 is removed from the housing 3116. The safety guard3130 is removed from the housing 3116 by pulling the safety guarddistally in the direction of arrow R.

When the safety guard 3130 is in its first position, the locking portion3134 inhibits or prevents actuation of the auto-injector 3006. Referringto FIG. 36, the locking portion 3134 includes a first engagement portion3128, or protrusion, that extends at least partially into the housing3116 of the auto-injector 3006 (shown in dashed lines). In someembodiments, the locking portion 3134 extends through an opening (notshown in FIG. 36) of the base 3158 movably coupled to the distal endportion 3156 of the housing 3116, similar to the opening 3522 defined bybase 3520 as illustrated in FIG. 14. The locking portion 3134 isconfigured to keep separate the projections of the actuator, similar toprojections 3548 of actuator 3510 illustrated in FIG. 13, when thesafety guard 3130 is in its first position. As the safety guard 3130 ismoved from its first position to its second position, the lockingportion 3134 is removed from between the projections 3548. Thus, theprojections can be moved to actuate the auto-injector as previouslydescribed.

When the safety guard 3130 is in its first position, the needle guardportion 3136 substantially covers the needle (not shown) of theauto-injector 3006. As the safety guard 3130 is moved to its secondposition, the sheath retaining portion 3154 remains coupled to thesheath 3152, and thus sheath is removed from its position covering theneedle.

The second engagement portion 3138 of the safety guard 3130 isconfigured to be selectively coupled to at least a portion of thehousing 3116 when the safety guard 3130 is in its first position. Thesecond engagement portion 3138, for example, can assist in guiding andremoving the safety guard 3130 by balancing the safety guard relative tothe housing 3116. In other words, as the safety guard 3130 is moved toits second (or removed) position, the second engagement portion 3138inhibits the safety guard 3130 from becoming skewed, and restrictingmovement of the first engagement portion 3128. In some embodiments, thesecond engagement portion 3138 can be coupled to the housing 3116 toprevent unwanted movement of the safety guard 3130 away from thehousing, such as via a resistance fit with the housing.

In some embodiments, the safety guard 3130 is constructedmonolithically. In other embodiments, the safety guard can beconstructed from separate components. For example, one or more of thebase portion, locking portion and/or needle guard portion can beconstructed separately and then coupled to the other portions. Althoughthe illustrated embodiment shows the second engagement portion 3138 asbeing disposed at or proximate to an edge of the base portion 3132, insome embodiments, the second engagement portion 3138 can be disposedelsewhere on the base portion. Although the first engagement portion3128, or locking member, is illustrated as being at or proximate to anedge of the base portion 3132, in some embodiments, the first engagementportion 3128 can extend from another portion of the base portion.

In some embodiments, a sleeve covers all or at least a substantialportion of the auto-injector. For example, as illustrated in FIG. 40,the sleeve 3180 covers substantially all of the safety guard (not shown)and the housing 3182 of the auto-injector 3007. The sleeve 3180 can beconfigured for use in an embodiment having only a safety lock or aseparate needle guard and safety lock. The sleeve 3180 has a firstposition in which the sleeve is configured to substantially cover thehousing 3182, as illustrated in FIG. 40, and a second position in whichthe sleeve is configured to be removed from the housing 3182 by pullingthe sleeve distally in the direction of arrow S, as illustrated in FIG.41.

Although the safety lock is described as having a first engagementportion and a second engagement portion, in some embodiments, the safetylock has only a first engagement portion. For example, as illustrated inFIGS. 42 and 43, a safety lock 3170 includes a locking portion 3174 anda needle guard portion 3176. The locking portion 3174 has a firstengagement portion 3178 disposed on the base portion 3172 of the safetylock. The first engagement portion 3178 extends proximally from the baseportion 3172. The needle guard portion 3176 includes a sheath 3192 and asheath retaining portion 3194. The sheath retaining portion 3194 extendsproximally from the base portion 3172 and is coupled to the sheath31924. The sheath retaining portion 3194 is coupled to the sheath 3192similar to the coupling of the sheath 3820 and sheath retainer 3840 asdescribed in detail above with reference to FIG. 8. The safety lock 3170is removed by pulling the safety lock distally in the direction of arrowS as shown in FIG. 41, away from housing 3182. When the safety lock 3170is in its second (or removed) position, the first engagement portion3178 is removed from between the projections of the system actuator rod(not shown in FIG. 41), and thus the auto-injector 3007 can be actuated.

In some embodiments, the locking member, distal end cap, safety guard,or sleeve are configured to mate or otherwise interface with the housingto prevent actuation of the auto-injector. The connection between thehousing and the sleeve, for example, can be a snug fit and can be aninterlocking connection. For example, in some embodiments, some forcemust be applied to remove the distal end cap, safety guard, or sleevefrom the housing.

FIG. 43 is a flowchart of an embodiment of a method 10000 formanufacturing a medicament delivery apparatus. At 10010, a medicamentcontainer is filled with a predetermined amount of medicament. Forexample, the medicament container can be filled with a predeterminedamount of epinephrine. As used herein, filling the medicament containerincludes putting medicament into the container, not necessarily fillingthe container to capacity. The filling of the medicament containeroccurs in a sterile environment. In some embodiments, the container canbe filled with a second medicament. In such an embodiment, the secondmedicament can be any constituent of a medicament, including water. Oncethe medicament container is filled, a seal can be placed on thecontainer to prevent leakage and/or contamination of the medicament. Atactivity 10020, the medicament container is removed from the sterileenvironment. For example, the medicament container can be filled in afirst sterile manufacturing facility, and then the filled containers canbe transported to a second facility, which is not necessarily a sterilefacility, to continue assembly of the apparatus.

At 10030, at least a portion of a needle is inserted into a needle hubdisposed in or on a housing. At 10040, a needle cover, or sheath, isinstalled over at least a portion of the needle so that the needle coversubstantially covers the portion of the needle extending from the needlehub. For example, a needle cover constructed of at least one ofpolyethylene, high density polyethylene, polypropylene,polytetrafluoroethylene, thermoplastic polyurethane, rubber, a polymer,or an elastomer can be installed to cover at least a portion of theneedle extending from the needle hub. When the needle cover isinstalled, the needle cover can also be coupled to the needle hub. Forexample, in some embodiments the needle cover includes a recessedportion configured to be coupled to a corresponding protrusion on theneedle hub. In some embodiments, the recessed portion and the protrusionforms a seal that is resistant to microbial penetration. One or both ofthe insertion of the needle into the needle hub 10030 and installing theneedle cover 10040 can occur in a non-sterile environment.

At 10050, the needle is sterilized. Various sterilization techniques maybe utilized. In some embodiments, a suitable sterilization techniqueincludes the use of one or more of ethylene oxide, gamma radiation,e-beam radiation, ultraviolet radiation, steam, plasma, or hydrogenperoxide. In some embodiments, the needle is sterilized prior toinstalling the needle cover. In some embodiments, the needle issterilized after the needle cover is installed. For example, in someembodiments, the needle cover is installed and then a gas sterilant isconveyed through at least a portion of the needle cover. The needle issterilized using a gas sterilization technique that can penetrate one ormore pores of a porous needle cover. In some embodiments, the needle canbe sterilized using a gas sterilization technique that can penetrate oneor more pores of a porous needle cover, but that will not react with amedicament in a medicament container disposed in the housing.

In some embodiments, the gas sterilant is conveyed through a valvedisposed on the needle cover. For example, the valve may be a one-waycheck valve, a spring-loaded valve, a self-sealing membrane, or thelike.

At 10060, the medicament container is disposed in the housing. At 10070,a needle guard assembly is coupled to at least one of a distal endportion of the housing or an actuator (or base portion) coupled to thehousing. In some embodiments, the coupling includes coupling a one piecesafety guard that is configured to prevent actuation of the apparatusand to receive at least a portion of the needle cover. In someembodiments, the coupling includes first coupling an actuation guard, orlocking member, configured to prevent actuation of the apparatus, andthen coupling a needle guard configured to receive at least a portion ofthe needle cover and to prevent movement of the locking member when theneedle guard is coupled to the housing or the base portion.

Although disposing the medicament container in the housing isillustrated and described as occurring after the needle cover isinstalled over at least a portion of the needle, in some embodiments,the medicament container is attached to the needle hub when the needlecover is installed over at least a portion of the needle.

Although only the needle is illustrated and described as beingsterilized, in some embodiments, one or more of the needle hub, needlecover, and medicament container are sterilized in addition to the needlebeing sterilized. The sterilization of the needle hub, needle cover,medicament container and needle can occur substantially simultaneouslyor at different times.

Although the flowchart in FIG. 43 presents each activity formanufacturing an auto-injector in a particular order, the variousactivities can occur in a different order. For example, the medicamentcontainer can be filled with medicament after the needle has beensterilized. In another example, the medicament container can be disposedin the housing prior to inserting the portion of the needle into theneedle hub.

While various embodiments of the invention have been described above, itshould be understood that they have been presented by way of exampleonly, and not limitation. Where methods described above indicate certainevents occurring in certain order, the ordering of certain events may bemodified. Additionally, certain of the events may be performedconcurrently in a parallel process when possible, as well as performedsequentially as described above.

Although various embodiments have been described as having particularfeatures and/or combinations of components, other embodiments arepossible having a combination of any features and/or components from anyof embodiments where appropriate. For example, in some embodiments, thesleeve 3180 illustrated in FIG. 40 can be used in connection with theauto-injector 3002, 3004, 3006. Additionally, any of the components ofthe needle guard and safety lock can be interchanged with similarcomponents in similar embodiments.

1. An apparatus, comprising: a housing having a distal end portion and aproximal end portion; a needle configured to move between a firstposition and a second position, in the first position the needle iscontained within the housing, in the second position at least a portionof the needle extends from the housing; an energy storage member havinga first configuration and a second configuration, the energy storagemember configured to produce a force when moving between its firstconfiguration and its second configuration to move the needle from itsfirst position to its second position; an actuator configured to movethe energy storage member from its first configuration to its secondconfiguration; a locking member configured to be movably coupled to thedistal end portion of the housing such that the locking member can bemoved between a first position and a second position, when the lockingmember is in its first position, the locking member is configured toengage the actuator to prevent the actuator from moving the energystorage member to the second configuration; and a needle guard removablycoupled to the distal end portion of the housing.
 2. The apparatus ofclaim 1, wherein the needle guard is configured to receive the needlewhen the needle is in its first position.
 3. The apparatus of claim 1,wherein the needle guard includes a sheath configured to receive theneedle and a sheath retainer configured to retain the sheath within thehousing.
 4. The apparatus of claim 1, wherein the needle guard includesa sheath having a proximal end portion and a distal end portion, thesheath defining an opening configured to receive at least a portion ofthe needle.
 5. The apparatus of claim 1, wherein the needle guardincludes a sheath configured to receive the needle, the sheath beingconstructed from a rigid material.
 6. The apparatus of claim 1, whereinthe needle guard includes a sheath having a proximal end portion and adistal end portion, the sheath defining an opening configured to receiveat least a portion of the needle, the sheath defining a recessed portionwithin the opening, the recessed portion configured to engage acorresponding protrusion on a needle hub coupled to the needle, theneedle hub being disposed within the housing.
 7. The apparatus of claim1, wherein the needle guard includes a sheath and a sheath retainer, thesheath retainer having a proximal portion and a distal portion, theproximal portion including at least one protrusion configured to engageat least one corresponding recess on at least one of the distal endportion of the housing or a base movably coupled to the distal endportion of the housing, at least a portion of the sheath disposablewithin an opening defined by the distal portion of the sheath retainer.8. The apparatus of claim 1, wherein the needle guard includes a sheathretainer configured to be coupled to the housing, the sheath retainerconfigured to at least partially cover the locking member and inhibitmovement of the locking member when the sheath retainer is coupled tothe housing.
 9. The apparatus of claim 1, wherein: the actuator includesa movable actuation member; and the locking member is configured toprevent movement of the movable actuation member when the locking memberis in its first position.
 10. The apparatus of claim 1, wherein thelocking member is removed from the housing when the locking member is inits second position.
 11. The apparatus of claim 1, wherein the lockingmember has a first end and a second end, the second end including twoextended portions configured to be disposed about a portion of theactuator when the locking member is in its first position, at least oneof the extended portions including an inwardly facing protrusion, theinwardly facing protrusion configured to engage at least one of thedistal end portion of the housing or a base movably coupled to thedistal end portion of the housing.
 12. The apparatus of claim 11,wherein at least one of the extended portions defines a recessconfigured to receive a portion of the needle guard when the needleguard is coupled to the distal end portion of the housing.
 13. Theapparatus of claim 11, wherein: the actuator includes an actuation rodhaving a plurality of projections; and the first end of the lockingmember includes an inwardly extending locking protrusion configured toextend between the plurality of projections of the actuation rod, thelocking protrusion configured to inhibit actuation of the actuator whenthe locking member is in its first position.
 14. The apparatus of claim11, wherein: the actuator includes an actuation rod having a pluralityof projections; and the first end of the locking member includes aninwardly extending locking protrusion configured to extend between theplurality of projections of the actuation rod, the locking protrusionconfigured to prevent the plurality of projections from moving inwardlytowards each other.
 15. The apparatus of claim 1, wherein the lockingmember is configured to move along an axis normal to a longitudinal axisof the needle.
 16. The apparatus of claim 1, wherein the needle guard isconfigured to engage the locking member to inhibit movement of thelocking member from its first position to its second position when theneedle guard is coupled to the distal end portion of the housing. 17.The apparatus of claim 1, wherein the needle guard includes an innermember configured to substantially cover at least a portion of theneedle and an outer member configured to be coupled to the inner memberand the distal end portion of the housing, the inner member being asubstantially impermeable microbial barrier and configured to allow asterilant gas to pass therethrough.
 18. The apparatus of claim 1,wherein at least a portion of the needle guard is substantiallyimpermeable to microbial penetration and is configured to allow asterilant gas to pass therethrough.
 19. The apparatus of claim 1,wherein the needle guard is configured to substantially cover thelocking member.
 20. The apparatus of claim 1, further comprising asleeve having a first position and a second position, the sleeve beingconfigured to cover at least a portion of the housing when the sleeve isin its first position, the sleeve being configured to be removed fromthe housing when the sleeve is in its second position.
 21. An apparatus,comprising: a housing; and a safety guard including a locking portionand a needle guard portion, the locking portion configured to inhibitactuation of a medicament delivery device, the needle guard portionconfigured to substantially cover a needle of the medicament deliverydevice, the safety guard having a first position in which the safetyguard is configured to be selectively coupled to at least one of thehousing or a base movably coupled to the housing and a second positionin which the safety guard is removed from the housing.
 22. The apparatusof claim 21, wherein the needle guard portion includes a sheath and asheath retaining portion, the sheath defining an opening configured toreceive at least a portion of the needle, the sheath being removablycouplable to the sheath retaining portion, the sheath retaining portionbeing configured to be coupled to the housing.
 23. The apparatus ofclaim 21, wherein the needle guard portion includes a sheath and asheath retaining portion, the sheath defining an opening configured toreceive at least a portion of the needle, the sheath being removablycouplable to the sheath retaining portion, the sheath retaining portionbeing configured to be coupled to the housing, the sheath beingconstructed from a rigid material.
 24. The apparatus of claim 21,wherein the safety guard includes a base portion, the locking portionbeing a protrusion extending from the base portion of the safety guard.25. The apparatus of claim 21, wherein the safety guard includes a baseportion, wherein the locking portion includes a protrusion extendingproximally from the base, the protrusion being configured to extendbetween a plurality of projections of an actuator of the medicamentdelivery device when the safety guard is in its first position.
 26. Theapparatus of claim 21, wherein the safety guard includes a base portion,the base portion having a first end and a second end, the lockingportion being disposed on the first end and including a first engagementportion, the base portion including a second engagement portion disposedon the second end and configured to be selectively coupled to at least aportion of the housing when the safety guard is in its first position.27. The apparatus of claim 21, wherein the needle guard portion includesa sheath, the sheath being a substantially impermeable microbial barrierand being configured to allow a sterilant gas to pass therethrough. 28.The apparatus of claim 21, further comprising a distal end capconfigured to selectively engage the housing, the distal end capconfigured to substantially cover at least a portion of the safety guardwhen the distal end cap is engaged with the housing.
 29. The apparatusof claim 21, further comprising a distal end cap having a first positionin which the distal end cap is removably coupled to a distal end portionof the housing and in which the distal end cap is configured tosubstantially cover the safety guard, and a second position in which thedistal end cap is removed from the housing.
 30. An apparatus,comprising: a needle guard configured to cover at least a portion of aneedle of a medical injector, the needle guard configured tosubstantially prevent microbes from passing therethrough, the needleguard configured to allow a sterilant gas to pass therethrough.
 31. Theapparatus of claim 30, wherein the needle guard is porous.
 32. Theapparatus of claim 30, wherein the needle guard is rigid.
 33. Theapparatus of claim 30, wherein the needle guard is constructed from atleast one polymer or elastomer.
 34. The apparatus of claim 30, whereinthe needle guard is constructed from at least one of polyethylene, highdensity polyethylene, polypropylene, polytetrafluoroethylene,thermoplastic polyurethane, rubber, or an elastomer.
 35. The apparatusof claim 30, wherein the needle guard includes a valve configured toallow sterilant gas to pass therethrough.
 36. An apparatus, comprising:a housing; a medicament injector disposable within the housing, themedicament injector including a needle having a first position and asecond position, in the first position the needle is contained withinthe housing, in the second position at least a portion of the needleextends from the housing; and a porous needle guard removably coupled tothe distal end portion of the housing, the porous needle guard beingconstructed from a microbial resistant material.
 37. The apparatus ofclaim 36, wherein the porous needle guard includes at least oneprotrusion configured to engage a corresponding recess in the housing.38. The apparatus of claim 36, wherein the porous needle guard includesat least one recess configured to receive a corresponding protrusion ofat least one of the housing or the medicament injector.
 39. Theapparatus of claim 36, wherein the porous needle guard is constructedfrom at least one of polyethylene, high density polyethylene,polypropylene, polytetrafluoroethylene, thermoplastic polyurethane,rubber, or an elastomer.
 40. A method, comprising: inserting at least aportion of a needle into a needle hub disposed in a housing; installinga needle cover over at least a portion of the needle to substantiallycover a portion of the needle extending from the needle hub; andsterilizing the needle after installing the needle cover.
 41. The methodof claim 40, wherein at least one of the inserting at least a portion ofa needle into a needle hub and the installing a needle cover isperformed in a non-sterilized environment.
 42. The method of claim 40,wherein the sterilizing the needle includes using a gas sterilizationtechnique.
 43. The method of claim 40, wherein the sterilizing theneedle includes conveying a sterilant gas through a portion of theneedle cover.
 44. The method of claim 40, wherein the installing aneedle cover includes installing a porous needle cover over at least aportion of the needle.
 45. The method of claim 40, wherein thesterilizing of the needle includes using a gas sterilization techniqueoperative to penetrate one or more pores of the needle cover.
 46. Themethod of claim 40, wherein sterilizing the needle includes using asterilization technique including at least one of ethylene oxide, gammaradiation, e-beam radiation, ultraviolet radiation, steam, plasma, orhydrogen peroxide.
 47. The method of claim 40, wherein the installing aneedle cover includes installing a needle cover constructed of at leastone of polyethylene, high density polyethylene, polypropylene,polytetrafluoroethylene, thermoplastic polyurethane, rubber, or anelastomer.
 48. The method of claim 40, further comprising: disposing amedicament container in the housing, the medicament container containinga predetermined amount of a medicament.
 49. The method of claim 40,further comprising: disposing a medicament container in the housing, themedicament container containing a predetermined amount of epinephrine.